Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L9/00—Rigid pipes
  • F16L9/12—Rigid pipes of plastics with or without reinforcement
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B1/00—Layered products having a non-planar shape
  • B32B1/08—Tubular products
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D23/00—Producing tubular articles
  • B29D23/001—Pipes; Pipe joints
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
  • B32B27/304—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/34—Layered products comprising a layer of synthetic resin comprising polyamides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
  • B32B37/12—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by using adhesives
  • B32B37/1207—Heat-activated adhesive
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/04—Interconnection of layers
  • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L11/00—Hoses, i.e. flexible pipes
  • F16L11/04—Hoses, i.e. flexible pipes made of rubber or flexible plastics
  • F16L11/08—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall
  • F16L11/081—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall comprising one or more layers of a helically wound cord or wire
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
  • B29C35/02—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould
  • B29C35/08—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation
  • B29C35/0805—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation using electromagnetic radiation
  • B29C2035/0822—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation using electromagnetic radiation using IR radiation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/001—Combinations of extrusion moulding with other shaping operations
  • B29C48/0018—Combinations of extrusion moulding with other shaping operations combined with shaping by orienting, stretching or shrinking, e.g. film blowing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
  • B29C48/09—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/15—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor incorporating preformed parts or layers, e.g. extrusion moulding around inserts
  • B29C48/151—Coating hollow articles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/16—Articles comprising two or more components, e.g. co-extruded layers
  • B29C48/18—Articles comprising two or more components, e.g. co-extruded layers the components being layers
  • B29C48/21—Articles comprising two or more components, e.g. co-extruded layers the components being layers the layers being joined at their surfaces
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C63/00—Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor
  • B29C63/0065—Heat treatment
  • B29C63/0069—Heat treatment of tubular articles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C63/00—Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor
  • B29C63/02—Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor using sheet or web-like material
  • B29C63/04—Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor using sheet or web-like material by folding, winding, bending or the like
  • B29C63/08—Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor using sheet or web-like material by folding, winding, bending or the like by winding helically
  • B29C63/10—Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor using sheet or web-like material by folding, winding, bending or the like by winding helically around tubular articles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
  • B29C65/48—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
  • B29K2023/04—Polymers of ethylene
  • B29K2023/06—PE, i.e. polyethylene
  • B29K2023/0608—PE, i.e. polyethylene characterised by its density
  • B29K2023/065—HDPE, i.e. high density polyethylene
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2027/00—Use of polyvinylhalogenides or derivatives thereof as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2027/00—Use of polyvinylhalogenides or derivatives thereof as moulding material
  • B29K2027/06—PVC, i.e. polyvinylchloride
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2077/00—Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
  • B29K2995/0037—Other properties
  • B29K2995/005—Oriented
  • B29K2995/0051—Oriented mono-axially
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
  • B29K2995/0037—Other properties
  • B29K2995/005—Oriented
  • B29K2995/0053—Oriented bi-axially
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2009/00—Layered products
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2023/00—Tubular articles
  • B29L2023/22—Tubes or pipes, i.e. rigid
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/514—Oriented
  • B32B2307/518—Oriented bi-axially
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2323/00—Polyalkenes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2327/00—Polyvinylhalogenides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2367/00—Polyesters, e.g. PET, i.e. polyethylene terephthalate
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2377/00—Polyamides
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
  • Y10T428/1352—Polymer or resin containing [i.e., natural or synthetic]
  • Y10T428/139—Open-ended, self-supporting conduit, cylinder, or tube-type article
  • Y10T428/1393—Multilayer [continuous layer]

Definitions

• the present invention relates to a multilayer plastic pipe protected from deterioration of its properties when being used and when being handled.
• plastic pipes often have a low creep resistance under prolonged stress.
• the object of the invention is to solve the problems posed by the abovementioned known reinforcing systems, while maintaining the production cost within limits that are acceptable and competitive with ductile cast iron pipes.
• the invention relates to a multilayer plastic pipe protected from deterioration of its properties, when being used and when being handled, and formed from a tubular support based on a polymeric composition whereby the pipe is protected by two layers each comprising an unoriented polymeric composition, the first being compatible with the polymeric composition of the subjacent plastic and the second being an external layer, also serving as finishing coat.
• the invention relates to a multilayer pipe, that is to say a pipe formed from a tubular support covered with at least the protective layers, the outermost layer of which forms a continuous surface layer.
• the tubular support is a hollow object in the form of a tube. It consists, at least partly, of a polymeric composition.
• polymeric composition is understood to mean any material comprising at least one plastic based on a polymer made of synthetic resin.
• Plastics that are very suitable fall within the thermoplastics category.
• thermoplastic denotes any thermoplastic polymer, including thermoplastic elastomers, and blends thereof
• polymer denotes both homopolymers and copolymers (especially binary or ternary copolymers). Examples of such copolymers are, in a non-limiting manner: random copolymers, block copolymers and graft copolymers.
• thermoplastic polymer or copolymer whose melting point is below the decomposition temperature is suitable.
• Synthetic thermoplastics that have a melting range spread over at least 10 degrees Celsius are particularly suitable. Examples of such materials include those that exhibit polydispersity in their molecular weight.
• polyolefins polyvinyl halides, thermoplastic polyesters, polyketones, polyamides and copolymers thereof may be used.
• a blend of polymers or copolymers may also be used, as may a blend of polymeric materials with inorganic, organic and/or natural fillers such as, for example, but non-limitingly, carbon, salts and other inorganic derivatives, glass fibres, natural mineral fibres or polymeric fibres. It is also possible to use multilayer structures consisting of stacked layers bonded together, comprising at least one of the polymers or copolymers described above.
• Polymers often employed are polyvinyl chloride and high-density polyethylene. Excellent results have been obtained with polyvinyl chloride.
• the expression “protected from deterioration” is understood to mean a pipe whose strength capability under its environmental conditions is enhanced by envelopment of the pipe with at least one layer of material especially suitable for withstanding these conditions.
• the protective layers are specifically the special layers mentioned above that increase the strength capability of the pipe under its environmental conditions.
• These protective layers each comprise a polymeric composition of unoriented structure, that is to say a composition comprising, as polymers, only those whose molecular chains do not have any particular orientation.
• the first protective layer is compatible with the polymeric composition of the subjacent plastic.
• compatible means that the polymeric composition of which the protective layer is composed, is inert from the chemical standpoint vis-a-vis the subjacent plastic and the physical composition of which protective layer is such that, in the melt state, it may easily blend into this subjacent plastic without giving rise to segregation phenomena.
• the compatibility may also imply easy adhesion of one layer to the other.
• polymeric compositions suitable for the first protective layer are those comprising polyvinyl halides and polyolefins.
• Polyvinyl chloride has given excellent results.
• the second protective layer is a finishing coat, that is to say an external layer that fixes the external dimensions of the pipe and the nature and finish of its surface.
• the second protective layer may have a composition identical to or different from that of the first layer. In particular, it may be made of the same polymeric material as that of the first layer. Polyvinyl chloride has also given good results in the composition of this second protective layer.
• the support comprises a polymeric composition of biaxially oriented structure.
• biaxially oriented is understood to mean a polymeric structure in which at least 20% by weight of the molecular chains of the polymers that are involved in its composition are arranged in two different directions. Preferably, the two directions are mutually perpendicular.
• Any type of thermoplastic polymer that lends itself easily to its molecular chains being oriented may be chosen for polymers with oriented chains. Examples of such polymers are polyolefins, polyvinyl halides, polyamides and copolymers thereof.
• a second advantageous variant of the pipe according to the invention is the one in which a reinforcing layer consisting of at least two thicknesses of reinforcing tapes comprising an oriented polymeric composition is placed between the support and the first protective layer.
• a reinforcing layer consisting of at least two thicknesses of reinforcing tapes comprising an oriented polymeric composition is placed between the support and the first protective layer.
• it is the oriented character of the polymeric composition of the reinforcing tapes that provides the pipe with effective reinforcement.
• the term “reinforced pipe” is understood to mean a pipe in which the intrinsic mechanical properties of the base material composition of which the pipe is composed are modified by the presence of an additional material composition that differs from this base material and, by its presence, increases the mechanical strength.
• the base material composition is a polymeric composition that represents at least 40% by weight of the total weight of the reinforced pipe.
• the base polymeric composition is that found in the support.
• the additional material composition is formed by the composition of the reinforcing layer.
• oriented polymeric composition means in this case that the polymeric composition comprises at least one oriented polymer.
• the reinforcing layer may comprise a single oriented polymeric composition. Alternatively, it may also comprise a blend of several polymeric compositions and optionally of non-polymeric additives, at least one of the polymers of which is oriented.
• the polymer may be any thermoplastic polymer that can be present in the tapes in oriented form, that is to say having at least 20% by weight of its constituent molecular chains lying in the same direction. Preferably, the direction of orientation is that of the length of the tape. Any type of thermoplastic polymer lending itself well to its molecular chains being oriented may be chosen for the oriented polymer. In general, an oriented polymer whose nature is the same as that of the polymers commonly used for producing pipes that have to withstand pressure is used. Advantageous examples of such polymers in the case of a support made of high-density polyethylene (HDPE) are, non-limitingly, multimodal HDPE resins and crosslinkable resins.
• HDPE high-density polyethylene
• the two thicknesses of reinforcing tapes are wound around the support in such a way that the second thickness completely covers the first around the support.
• an advantageous alternative to the second variant described above consists in the first thickness of tapes of the reinforcing layer being adhesively bonded to the support, that is to say fastened to the latter by means of an adhesive of the usual suitable kind.
• an advantageous embodiment of the pipe is for its first protective layer to be formed by at least one thickness of unoriented tapes wound around the pipe.
• one particularly advantageous embodiment is the one in which the first protective layer is bonded to the subjacent polymeric composition.
• the invention also relates to a process for producing a multilayer plastic pipe protected from deterioration of its properties when being used and when being handled, in which:
• the first protective layer is applied to a tubular support based on a polymeric composition by winding at least one thickness of tapes of unoriented polymeric composition compatible with the polymeric composition of the subjacent plastic;
• the second protective layer comprising an unoriented polymeric composition is then applied by overextrusion, forming the external finishing coat.
• the second protective coating may be applied by overextrusion using any overextrusion technique well known per se, in particular the overextrusion techniques used in the plastic pipe manufacturing industry.
• overextrusion techniques used in the plastic pipe manufacturing industry.
• An example of these techniques is the use of a hollow ring-shaped die through the middle of which the pipe passes, the said die allowing a controlled amount of polymeric composition to be uniformly and continuously deposited around the periphery of the pipe.
• a reinforcing layer formed from at least two thicknesses of tapes comprising an oriented polymeric composition is applied, to a support comprising a polymeric composition of unoriented structure, by winding tapes in such a way that the tapes of one particular thickness make, with those of the adjacent thickness, a similar angle, but of opposite sign, relative to the axis of the pipe;
• the expression “similar angle” means an angle at least equal to the same angle less 5 degrees of angle.
• the expression “similar angle” also includes an angle at most equal to the same angle plus 5 degrees of angle.
• this expression means an angle at least equal to the same angle less 2 degrees of angle. Also preferably, it includes an angle at most equal to the same angle plus 2 degrees of angle.
• the adhesive of the reinforcing layer is activated by irradiation of the pipe with infrared radiation while the pipe is being formed;
• the precoating operation may be carried out immediately before application of the reinforcing tapes, or else at a later time, at another moment before manufacture of the pipe. Likewise, the operation may be performed on one side of the tapes, or on both. Preferably, it is performed on one of the sides.
• This technique advantageously makes it possible to apply the reinforcing tapes without heating them beforehand and then to easily control the flow of heat radiated by the infrared radiation through the first protective layer so that it does not destroy the orientation of the polymeric composition of the reinforcing tapes.
• the adhesive of the reinforcing tapes may also be activated in several separate steps, after each application of a thickness of tapes, by successive irradiations of the pipe with infrared radiation while the pipe is being formed.
• At least one of the protective layers may, as a variant, also be bonded to the subjacent structure by means of an adhesive.
• This adhesive may, for example, be activated by infrared irradiation.
• a 360 mm wide tape of oriented polyvinyl chloride (PVC) was produced by drawing a 400 mm film of unoriented SOLVIN® 266RC PVC with a draw ratio of 400% by means of a laboratory calender. After drawing, this tape had a thickness of 400 ⁇ m, an elastic modulus of 5 GPa and a tensile strength of 175 MPa.
• this strip was coated on one side only with a heat-activated water-soluble polymer adhesive of the LUPHEN®D200A brand.
• the coated tape was wound around a pipe made of POLVA® PVC having an outside diameter of 50 mm, an outside diameter/wall thickness ratio of 34 and of ordinary quality from the standpoint of its pressure resistance (nominal acceptable pressure of 0.75 MPa).
• the winding was carried out so as to form two layers each crossed at an angle of 55° to the axis of the tube.
• the outer surface of the tapes wound around the pipe was then heated to 75° C. for 5 seconds.
• the pipe obtained was then covered with a further layer of SOLVIN® 266RC PVC, to which additives had been added beforehand, in the form of a 400 ⁇ m thick unoriented tape completely covering it and precoated with the LUPHEN®D200A adhesive.
• the additives comprised a mixture of a carboxylate-type tin stabilizer (3% by weight relative to the PVC), a processing aid (1% by weight of polymethyl methacrylate) and a lubricant (1% by weight) composed of a mixture of calcium stearate, paraffin wax and oxydized polyethylene wax.
• the adhesive was then activated under the same conditions as those described above in the case of the oriented tapes.
• the tube obtained was then covered with a finishing coat made of SOLVIN® 266RC PVC (a grade usually employed for pipes 300 ⁇ m in thickness), to which the same additives as those described above were added, by passing the pipe through an annular die, then through a sizing device and into a cooling tank filled with water at room temperature.
• SOLVIN® 266RC PVC a grade usually employed for pipes 300 ⁇ m in thickness
• the pipes according to the invention have a substantially better burst pressure than an unreinforced pipe. It is even possible to save about 25% by weight of material relative to a conventional pipe, while nevertheless increasing the burst strength by 15% (reinforced and protected POLVA® pipe 3.2 mm thick).

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Laminated Bodies (AREA)
• Rigid Pipes And Flexible Pipes (AREA)
• Materials For Medical Uses (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)

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• 2001
  • 2001-04-27 BE BE2001/0292A patent/BE1014146A3/fr not_active IP Right Cessation
• 2002
  • 2002-04-25 DE DE60220791T patent/DE60220791T2/de not_active Expired - Lifetime
  • 2002-04-25 PT PT02735308T patent/PT1397248E/pt unknown
  • 2002-04-25 KR KR1020037013909A patent/KR100901747B1/ko not_active Expired - Fee Related
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  • 2002-04-25 WO PCT/EP2002/004669 patent/WO2002087874A1/fr not_active Ceased
  • 2002-04-25 AT AT02735308T patent/ATE365105T1/de active
  • 2002-04-25 EA EA200301186A patent/EA004977B1/ru not_active IP Right Cessation
  • 2002-04-25 EP EP02735308A patent/EP1397248B1/fr not_active Expired - Lifetime
• 2003
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• 2007
  • 2007-01-05 US US11/620,220 patent/US20070107830A1/en not_active Abandoned

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